UNORIENTED ELECTRICAL STEEL SHEETS AND METHODS FOR MAKING THEM

Abstract

An unoriented electrical steel sheet according to an embodiment of the present invention comprises, in wt %, Si: 1.5 to 6.0%, Al: 0.1 to 2.0%, Mn: 2.0% or less (excluding 0%), and Cu: 0.002 to 0.100%, with the remainder being Fe and unavoidable impurities, wherein the ratio (AlMAX / Al5μm) of the maximum Al content (AlMAX), as measured when determining the Al content in the thickness direction from the surface of the steel sheet to a point 5 μm in the steel sheet, to the Al content (Al5μm) at a point 5 μm in the steel sheet from the surface of the steel sheet is 5.0 or less, and wherein the amount of Al aggregates having a particle diameter of 500 nm or more in the region from the surface of the steel sheet to 5 μm in the steel sheet is 5 or less per 100 μm length of the steel sheet.